Xamarin.forms: XamlC throws Object reference not set to an instance of an object on DevOps

[cheles]

Description

XamlC crashes in Xamarin.Forms project under DevOps build with "Object reference not set to an instance of an object ".

Expected Behavior

XF solution should build in DevOps as it does in local VS

Actual Behavior

Error thrown: `

 error : Object reference not set to an instance of an object. [C:\agent\_work\4\s\Controller\ControllerApp\ControllerApp.csproj]
2019-03-18T09:19:56.8468956Z      at Xamarin.Forms.Build.Tasks.TypeReferenceExtensions.<GetMethods>d__14.MoveNext()
2019-03-18T09:19:56.8468994Z      at Xamarin.Forms.Build.Tasks.TypeReferenceExtensions.<GetMethods>d__14.MoveNext()
2019-03-18T09:19:56.8469381Z      at System.Linq.Enumerable.<ConcatIterator>d__59`1.MoveNext()
2019-03-18T09:19:56.8469437Z      at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
2019-03-18T09:19:56.8469484Z      at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
2019-03-18T09:19:56.8469524Z      at Xamarin.Forms.Build.Tasks.TypeReferenceExtensions.GetImplicitOperatorTo(TypeReference fromType, TypeReference toType, ModuleDefinition module)
2019-03-18T09:19:56.8469580Z      at Xamarin.Forms.Build.Tasks.SetPropertiesVisitor.<Add>d__54.MoveNext()
2019-03-18T09:19:56.8469618Z      at Xamarin.Forms.Build.Tasks.ILProcessorExtensions.Append(ILProcessor processor, IEnumerable`1 instructions)
2019-03-18T09:19:56.8469655Z      at Xamarin.Forms.Build.Tasks.SetPropertiesVisitor.Visit(ElementNode node, INode parentNode)
2019-03-18T09:19:56.8469691Z      at Xamarin.Forms.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
2019-03-18T09:19:56.8469754Z      at Xamarin.Forms.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
2019-03-18T09:19:56.8469788Z      at Xamarin.Forms.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
2019-03-18T09:19:56.8469830Z      at Xamarin.Forms.Xaml.ElementNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
2019-03-18T09:19:56.8469882Z      at Xamarin.Forms.Xaml.RootNode.Accept(IXamlNodeVisitor visitor, INode parentNode)
2019-03-18T09:19:56.8469923Z      at Xamarin.Forms.Build.Tasks.XamlCTask.TryCoreCompile(MethodDefinition initComp, MethodDefinition initCompRuntime, ILRootNode rootnode, Exception& exception) (TaskId:535)`

Basic Information

XF project builds successful in local VS and from MSBuild command line.
DevOps has MSBuildVersion = 15.9.21.

• Platform Target Frameworks: Android

I can send the output log to assignee as it's a non-public log

[cheles]

@samhouts @StephaneDelcroix any updates on this from your side?

[samhouts]

We're having trouble reproducing this issue. We're working on it, and hopefully we will have more information next week. Thanks!

[cheles]

hey @samhouts any updates from your side? let me know if you need further logs

[samhouts]

@cheles No update. Please do send me the logs. Thanks!

[cheles]

@samhouts customer discontinued the case for now. how do you want to proceed with this?

[samhouts]

@cheles Since we were unable to reproduce it, I guess we should go ahead and close this issue. However, do let me know if you have any ideas that would help us find the problem. Thanks!